geo-, ge- +

1. Energy in the form of natural heat flowing outward from within the earth and contained in rocks, water, brines, or steam.
2. Heat which is produced mainly by the decay of naturally occurring radioactive isotopes of thorium, potassium, and uranium in the earth's core.
3. An energy produced by tapping the earth's internal heat. At present, the only available technologies to do this are those that extract heat from hydrothermal convection systems, where water or steam transfer the heat from the deeper part of the earth to the areas where the energy can be tapped.

The amount of pollutants found in geothermal vary from area to area but may contain arsenic, boron, selenium, lead, cadmium, and fluorides. They also may contain hydrogen sulphide, mercury, ammonia, radon, carbon dioxide, and methane.

Getting the Earth's Heat

Geothermal power plants, which tap hot subterranean water or steam, are high on the lists of at least thirty states in the U.S. which are requiring utility companies to generate some portion of their electricity from such renewable sources.

Most utilities have not pursued geothermal energy primarily because up-front costs, including exploratory drilling, can be expensive since geothermal taps deep reservoirs, not groundwater, which collects much closer to the surface.

An extensive study recently released by the Massachusetts Institute of Technology has shown that the heat available under ground is surprisingly plentiful nationwide.

More information about special Geothermal Energy sources.

The rate of temperature change in soil and rock from the surface to the interior of the earth; on the average, estimated to be an increase of about +10°C per kilometer.

1. The extraction of valuable minerals from geothermal fluids; such as, market-grade silica from a geothermal brine.
2. The process of purposely transporting geothermal energy from beneath the earth for human use; that is, the building of a well and pipeline system to bring heated water to a power plant.

Heat pumps which consist of underground coils that transfer heat from the ground to the inside of a building.

An industrial heat-producing manufacturer in which the prime mover is a steam turbine: Geothermal plants are driven either by vapor produced from hot water or by natural condensation that derives its energy from the hotness found in rock formations of the earth.

Like other related "plant" references, this entry is apparently linked to the action of pressing on a shovel, or some other apparatus, with the "sole of the foot" in order to work the soil for the development of plants.

A subsurface system consisting of a large volume of hot water and steam trapped in a porous and fractured hot rock underneath a layer of impermeable rock.

Some reservoirs can be commercially developed as an energy source.

A localized geological environment in which circulating steam, or hot water, carries some of the earth's natural internal heat flow close enough to the surface to be utilized for productive human use.

Any technological system that makes use of this heat as an energy source; such as, to power an electrical power plant or to heat or to cool a building.

Pertaining to the internal heat of the earth; or heat generated in the interior of the earth.

An instrument for measuring subterranean temperatures.

1. The direct or indirect measurement or approximation of the temperatures at which geologic processes take place or have taken place.
2. The study of the earth's heat and temperatures, and their effects on geologic processes.
3. The study of the earth's heat and subsurface temperatures.
4. In geology, a mineral or aggregate of minerals whose presence defines the temperature range of limits within which the minerals were formed; also known as a geologic thermometer.

The practice of eating earth materials; especially, clay or chalk, as in famine-stricken areas.

1. An infection of the lungs or of the mouth and intestines caused by the fungus Geotrichum candidum.
2. A rare fungal infection of the mouth, respiratory tract, and digestive tract which can cause skin, bronchial, mouth, lung, and/or intestinal lesions. It is caused by fungi in the genus Geotrichum.
3. An infection by Geotrichum candidum, which may attack the bronchi, lungs, mouth, or intestinal tract; its manifestations resemble those of candidiasis (yeast infection). The "yeast" is normally present on the skin, in the intestinal tract, and with women, in the genital region.

1. A description of the response of plants toward the pull of gravity.
2. An organism that responds to the force of gravity with movement towards the center of the earth.

1. The response of a plant to gravity, as evidenced by growing patterns; such as, downward root growth and growth curvature.
2. Plant growth or movement in response to gravity: "Primary roots (tap roots) grow vertically towards gravity (positive geotropism) whereas primary shoots grow vertically away from gravity (negative geotropism), though the direction of shoot growth may also be modified by light."

1. An organism that becomes a temporary member of the soil fauna.
2. An organism found in a soil stratum of which it is not normally a resident.